<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>06_DOM操作2</title>
</head>
<body>
    <input type="text" id="i1">
    <input type="text" id="i2">
    <button onclick="f1()">点我查看</button>
    <hr>
    <h4>我是标题：<span id="ss"></span></h4>
    <button onclick="f2()">按钮</button>

<script>
    function f2(){
        //let spanE = document.querySelector('span');
        //let spanE = document.querySelector('#ss');
        let spanE = document.getElementById('ss');
        console.log(spanE);
        spanE.innerHTML = '我是修改后的内容';
    }
    function f1(){
        let inputE = document.querySelector('#i1');
        console.log(inputE);
        let num = document.querySelector('#i2').value;
        console.log(num,typeof num);
        num = parseFloat(num);
        console.log(num,typeof num);
    }
</script>

</body>
</html>